It is known, e.g. from U.S. Pat. No. 1,930,307, to mount a frame for such a map on or in the vicinity of a vehicular dashboard together with a magnifying glass. These prior devices, in which the map has to be fitted into the frame with a predetermined orientation, are not very convenient for the checking of details at locations on the map remote from the driver's seat. Thus, the driver cannot readily adjust the position of the map in its frame while operating the vehicle, having only one hand free for this purpose. Simpler devices using only a clip, e.g. as shown in German utility-model registration No. 1,665,099, have the drawback of affording limited support for the map which is thus liable to fold over, especially during summer driving with windows open, or to lose its hold and drop to the floor of the vehicle.